There have been various forms of wind-driven rotors heretofore designed. Some of these wind rotors are constructed for optimum performance within a narrow band wind velocities and are expensive to manufacture, while other forms of wind rotors are constructed to operate throughout wider bands of wind velocities. The latter forms are more desirable in that they are capable of generating power from the wind, but some are constructed so as to be relatively inefficient. The power generator in my prior U.S. Pat. No. 3,924,966 constitutes a wind rotor which is capable of operating throughout a reasonably wide band of wind velocities, but is limited to the total vane area thereof which may be included on a wind rotor of cylindrical configuration. Accordingly, a need exists for a wind rotor which is operable throughout a wide band of wind velocities and yet which will present considerable vane area to the wind for action thereon by the latter and which will thus be efficient in operation.